Analyses of clones transformed by the FUT8 and GMD siRNA tandem expression vector. The relative amounts of FUT8 (filled columns) and GMD (open columns) mRNA were quantified in the tandem siRNA expression vector-introduced LCA-resistant cells and parental cells (A). Each cell type was harvested after 3-day culture and the samples were analyzed by real-time PCR. Each mRNA amount was normalized to the amount of β-actin mRNA; the results are shown as the relative percent with respect to the parental cells (100%). The LCA reactivity of cells (32-05-12 (B), Ms705 (C), FG1 (D), and FG16 (E)) was analyzed after adaptation of the cells to serum-free medium. Each cell type was harvested after 6-day culture and stained with FITC-labeled LCA (filled peak) or FITC-labeled streptavidin (open peak) as a negative control, and the results were analyzed by FACS.